Is there a bounding boxes for particle system objects?
Not sure if their are bounding boxes for Particle systems but one way to create bounding boxes is by assigning the "Collision" property to a 3d Object like a Cube containing the Particle system and then treat it as a bounding box.
The below simulation is done by using a Wind Force field and using icospheres objects for Particle System under Newtonian Physics. The bounding Box -Cube in this case is provided the collision property under the Physics tab and its Z-tranperncy alpha (under material) is set to "0".   

However,inorder to show the limits of the Bounding Cube ,if a wireframe modifier is used the collision property no longer applies and there is no bounding.